Circuit breaker



June 1, 1943. w. H. FRANK EIAL' 2,320,355

CIRCUIT BREAKER 2 SheetsSheet 1 Filed Nov. 18, 1940 UMNQNRNNN June 1, 1943.

jg. ,3 OFF w. H. FRANK ET'AL CIRCUIT BREAKER Filed Nov. 18, 1940 2 Sheets-Sheei 2 INVENTORS m; MM

Patented June 1, 1943 CIRCUIT BREAKER William H. Frank and Joseph A. Messing, Detroit Mich., assignors to Bulldog Electric Products Company, Detroit, Mich., a corporation of West Virginia Application November 18, 1940, Serial'No. 366,032

6 Claims.

This application relates to circuit breakers and particularly to operating mechanisms therefor.

A circuit breaker consists of one or more stationary contacts, a corresponding number of movable contacts which are to be moved to and from the stationary contacts manually, and which also are to be moved from the stationary contacts automatically on the arising of an overload, and a mechanism for providing such movements for the movable contact or contacts. This application discloses such an operating mechanism in the appended drawings which disclose a multipole breakerwhich is an em odiment of the invention.

The circuit breaker mechanism disclosed operates with snap action on manual movement, and is trip free in that automatic or trip movement is free of any available manual restraint.

The parts may be so arranged that manual actuation is required for reclosing the circuit after an automatic operation; or, so that the parts move to reclose the circuit automatically after an automatic release operation whereby the breaker may operate cyclically to open and close the circuit automatically and without requiring a manual reclosing for circuit closing.

In these drawings,

Fig. 1 is an open front view of one embodiment;

Figs. 24 are side section views, as if on line 2-2, Fig. 1, with the parts shown in circuit closing position, open circuit position, and overload released or tripped position, respectively.

Referring to Figs. 1-4, it will be seen that these show an insulation base or body l having a back plate surmounted by a top plate which resiliently supports three separate stationary contacts l l adapted to be engaged by three movable contacts l2 mounted on an insulation plate l4 pivotally mounted at IS on side plates of the base; contacts l2 are connected through flexible straps and stationary straps IS in turn connected through solenoid coils I1 to load binding posts l8,

' fit within cam slots '28 in arms 29 pivotally mounted at 30 on'the side plates.

A bail 38 is pivotally mounted on the sides at alined points 31 and its bight 31a is connected through coiled tension springs 38 to the ends of the pintle 23. A- link 39 connected to one arm of the bail at point 40 is pivotally connected at 4| to a rocker handle 43 pivotally mounted at 44 on a side of the base.

Arms 29 are connected by a pin 49 and links to the plunge'rs 52 of the solenoid coils 11.

The operation is as follows:

For manual operation handle 43 is rocked forward and back on pivot 44, to and from the position of Figs. 2 and 3, to pull forward or push back on link 39 to cause forward and back movement of the bail 36 so that springs 38 pull forward or back on pintle 23 to extend (make) or collapse (break) the toggle22-23-24, as in Figs. 2 and 3, respectively. As springs 38 move, they are first extended, and then pass over pivot 26, for snap action.

When the toggle is collapsed (Fig. 3), plate l4 and movable contacts l2 are moved down, away from the stationary contacts ll. When the toggle 22-24 is extended (Fig. 2), the plate 14 and movable contacts I2 are caused to engage contacts I I with butt pressure and with the movable contacts locked in such position by the toggle. During all this action arms 29, pin 49, links 50, and plungers 52 are stationary, and rollers 21 move in slots 28 of arms 29, free and clear of the edges of such slots.

For overload release operation on any pole. any plunger 52 is moved up by an overload in any coil l1 and this action causes the corresponding link 50 to-move up to push pin 49 up, causing arms 29 to rock clockwise (Fig. 2) on their pivots 30 to push or cam the ends of the pintle 23 towards the back or base l0 to break the toggle and move plate 14 down for circuit opening.

'This moves springs 38 across the line 31--31a, and thus moves bail 36, and handle 43,.to reset them in the open circuit or "off" position of Figs. 3 and 4.

Handle movement thereafter causes movement of the toggle and rollers 21 to the on position of Fig. 2, and moves cam 28, links 58, and plungers 52 to the closed circuit or 011" position. In such movement rollers 21 move to the right (to Fig. 2), and these rollers cam arm 29, by riding on the lower edge of slot 28 therein to rock arm 29 down on its pivot 30 (to Fig. 2)-.

However, if the'handle be held in the closed circuit or on position of Fig. 2, during trip,"

springs 38, though moved across line 31-3111, will not move the ball 36 to the off position of Figs. 3-4, as above, following a trip movement; the toggle will break to open the circuit, on trip, whereupon the solenoids will become deenergized, and thereafter, springs 38 will restore or extend the toggle, once more to close the circuit, all this taking place automatically, as long as the handle is held and the overload persists, for cyclic of! and on movement. The location of pivot 31 for bail 36 is shown 3 such that, on trip movement with handle the bail and handle to the tripped position of Fig, 4. However, if, as might well be the case when desired, point 31 is not where shown,

but considerably nearer the back (to the left, Fig. 2) of the device, spring 38 will not be able to cross line 3l--3la for resetting of the manual parts to the off position (Figs. 3-4) but will leave them (bail and handle) in the on position of Fig. 2. Thus the optional location of point 31 determines whether or not the breaker will, after trip, have its manual parts left in on or off positions,

It will be observed that the movement of any plunger, by virtue of an overload in its corresponding coil l1, will cause arms 28 to rotate clockwise and move the plungers 52 of the remaining coils, which may not have an overload in them, correspondingly to close the air gap of these respective solenoids to such a point that the power of these additional solenoids will be obtained, even though there be no overload in their respective coils, but only a normal current therein, so as to be added to that of the overloaded solenoid to operate the arms 29 and thus cause the circuit breaker to open.

Thus, an overload in any one or more solenoids will initiate the necessary movement to cause rupturing of the circuit breaker; each solenoid coil initiates the movement, but when this movement is suiiicient to reduce the air gap in the other solenoids not overloaded, the power of the other solenoids, due to the current in them, is utilized to effect automatic circuit rupturing.

Since the connection between the handle and the toggle is established necessarily through the spring, toggle movement for trip" may be accomplished, despite the holding of the handle; though, if the handle be held, the toggle will be extended once more; but, though toggle movement, on trip, causes spring movement, or is opposed by the spring, the reverse is not true, for, on trip, the toggle is moved by the solenoids and not by the spring.

In the overload release operation the arms 29 function with respect to the rollers 21 and. the pintle 23 in a manner that may be described as a cam action, the edges of the slots 28 in arms 29 camming the rollers 21 backwardly from the position of Fig. 2 towards that of Fig. 4 to break the toggle and open the circuit. Thus, the solenoids l1 and their plungers 53 are given a mechanical advantage over the linkage to the extent desired by the designer of the operating mechanism.

The operating linkage for the movable contacts is seen to be of the toggle type, locking itself and holding itself in circuit closing position, and collapsing itself immediately when movement towards the circuit open position is started: in circuit closed position, the contacts are positively biased against each other due to the action of the springs 38 and also due to the fact that the toggle is extended or made when the parts reach circuit closed position, and the extended toggle locks or holds the contacts against each other.

It will be observed that the circuit breaker hereof may be utilized as a manually operable switch having a quick make and quick break free, spring 38 crosses the line 3l--31a to move magnets operate on the toggle linkage and thus, with a mechanical advantage, operate on the movable contacts so as to move them away from the stationary contacts on the arisingof overloads or short circuits; the parts are arranged in such a manner that when the magnets function in this fashion they operate in opposition to the force of the springs 38 and operate completely independently of and without the magnet force passing through the springs 38. Consequently, inasmuch as the springs 38 constitute the connection means between the handle and the movable contacts, the functioning of the magnets or solenoids to open the circuit on overloads cannot be restrained by holding of the handle andin this way the circuit breaker is made trip free, that is to say, the contacts may be opened positively without there being any possibility that opening is interfered with or delayed or restrained by mischievous or unintentional holding the manually accessible handle.

It will also be observed that the work performed by the magnets in-opening the circuit in opposition to the force ,of the springs 38 helps absorb the electrical energy that is stored in the circuit and that must be interrupted by the circuit breaker. In this way the stored energy is dissipated, not alone in the arcing that oc-- curs at the contacts, but part of such energy is utilized as an operating force to open the circuit breaker.

It will also be observed that the mechanism is so arranged that if the handle is held manually in on position while the circuit is being opened automatically, as on overload, the circuit breaker will reclose itself automatically and in this way, in the event the handle is not moved, for any length of time. the circuit breaker will function cyclically as an automatically reclosing and opening breaker. However, as soon as the handle is moved to off position, Fig. 3, during such cyclic action, following automatic opening the movement of the parts will terminate, with breaker on overload.

action wherein movement of the handle tensions the spring so that when the spring passes over center the toggle linkage is collapsed or extended to open or close the circuit with a snap action.

It will also be observed that the solenoids or It will be observed that the breaker hereof is a multi-polar breaker which employs a togglelinkage for operation of the movable contacts, with the linkage in turn operated either by the operating springs 38 or by the solenoids I! rather than operated directly by the springs or the operating force whereby a greater contact pressure can be obtained without at the same time imposing a diflicult obstacle to be overcome by the operating force, whether it be imanual I (springs) or automatic (magnet).

Now having described the embodiment herein disclosed, reference should be had to the claims which follow for a determination of the inventions sought to be protected herein.

We claim: 7

1. A multiple circuit breaker comprising a plurality of magnetic means responsive to overloads, there being an overload responsive magnetic means for each pole, each magnetic means including a coil and an armature, means interconnecting the several armatures whereby, when, on the arising of an overload in one pole, the coil of that pole responds to the overloadv in that pole to move its armature, that armature will move the interconnecting means to an extent sufiicient to move the remaining armatures closer to their coils, close enough so that the said coils, in which there are not yet any overloads will respond to the normal loads in them and cause their armatures to move further.

2. In a circuit breaker, a movable contact, a handle, a spring operatively connecting the handle and contact and alone establishing their interconnection whereby movement of the handle biases the spring thereafter to move the contact, a solenoid having a plunger which moves on overload in the solenoid and movable contact circuit, and means independent of the springindependently of the springmoves the contact from circuit closing position on overload, the connecting means being such that plunger movement on overload necessarily causes movement of the contact out of circuit closing position, free of the spring and handle, which need not move,

operatively connecting the plunger and the con tact whereby plunger movement, by its own force alone, and with no aid from the spring, and act-. ing on said connecting means independently of the spring moves the contact from circuit closing position on overload, the connecting means being such that plunger movement on overload necessarily causes movement of the contact out of circuit closing position, free of the spring handle, which need not move, and which will not move, if held, the'connecting means and spring being so free of each other that the spring and contact may be moved by the handle free of the connecting means and the plunger which will move only on overload.

4. In a circuit breaker, a movable contact, a

handle, a spring operatively connecting the handie and contact and alone establishing their interconnection whereby movement of the handle biases the spring thereafter to move the contact,

a solenoid having a plunger which moves on overload in the solenoid and movable'contact circuit,

and means independent of the spring and handle, operatively connecting the plunger and the contact whereby-plunger movement, by its own force alone, and with no aid from the spring, and acting on said connecting means independently of the spring moves the contact from circuit closing position on overload, the connecting means being such that plunger movement on overload necessarily causes movement of the contact out of circuit closing position, free of the spring and handle, which need not move, and which will not move, it held, the connecting means and spring being so free of each other that the spring and contact may be moved by the handle free of the connecting means and the plunger which will move only on overload, the connecting means and spring further being so related that the handle and spring will move automatically to opencircuit position, following an overload movement of the plunger and the connecting means and the contact, if and when the handle and spring are free so to move.

5. In a circuit breaker, a movable contact,-a handle, a spring operatively connecting the handle and contact and alone establishing their interconnection whereby movement of the handle biases the spring thereafter to move the contact, a solenoid having a plunger which moves on overload in the solenoid and movable contact circuit, and means independent of the spring and handle, operatively connecting the plunger and the contact whereby plunger movement, by its own force alone, and with no aid from the spring, and acting on said connecting means independently of the spring moves the contact from circuit closing position on overload, the connecting means being such that plunger movement on overload necessarily causes movement of the contact out of circuit closing position, free of the spring and handle, which need not move, and

which will not move, it held, the connecting means and spring being so free of each other that the spring and contact may be moved by the handle free of the connecting means and the plunger which will move only on overload, the connecting means and spring further being so related that the handle and spring will, if held against movement to open circuit position while the plunger, the interconnecting means, and the contact move to open circuit position, return the contact to closed circuit position automatically.

6-. In a circuit breaker, a movable contact, a handle, a spring operatively connecting the hendle and contact and alone establishing their interconnection whereby movement of the handle biases the spring thereafter to move the contact,

moves on overa solenoid having a plunger which load in the solenoidiand movable contact circuit, and means independent or the spring and handle, operatively connecting the plunger and the contact whereby plunger movement. by its own force alone, and with no aid from the spring, and acting on said connecting means independently of the spring moves the contact from circuit closing position on overload, the connecting means being such that plunger movement on overload necessarily causes movement of the contact out of circuit closing position, tree of the spring and handle, which need not move, and which will not move, it held, the connecting means and spring being so free of each other that the spring and contact may be moved by the handle tree of the connecting means and the plunger which will move only on overload, the spring being so connected to the contact that it unsuccessfully opposes the circuit opening force imparted to the contact by the plunger, in its movement responsive to overload.

\ WILLIAM H. FRANK JOSEPH A. 

